Huh, I never noticed that before.
Yeah, Obi-wan cuts off all his remaining organic limbs, making him a full quadriplegic amputee. It is funny, I always imagine that it cuts down on his force ability to an extent (especially if you bring Midichlorians into it), explaining why he’s not quite as force-active in the OT as he is in the PT. Also take for example how Luke got shot directly in his mechanical hand on Jabba’s sail barge, as if he isn’t as force sensitive in his fake limb. (Of course, Vader’s force choke hand motions would then have to be phantom muscle memory related to the force technique and technically not necessary.) (Also, it would really have to slow down his lightsaber dueling reactions as he’d have to direct the force to manipulate his artificial limbs rather than them being directly controlled by the force… Which strangely would be just about the decline in speed we see between PT duels and OT duels. [Obi-wan should have owned him on the Death Star, now that I think about it {unless he had force-arthritis}])
Anyway, if you use the Robocop footage past the point when he gets up and starts walking, you should consider putting an image of Darth Vader walking by in the TV screen he passes by displaying a live recording of him. (at 2:57 in the video)
I did hear this explanation before. Pretty sure it was official.
That was just a guess on my part, do you have a source?